Q: I agreed to be in a friend’s wedding, and unfortunately, she had to change the date to the day my boyfriend and I were going to Burning Man. When I told him I’d have to go to her wedding instead, he erupted in anger. He wants me to ask her to change the date, and says he’ll “never forgive me” if I don’t go with him. Now, we were only going to Burning Man together because he couldn’t take the whole week off, so instead of going with his friends, he decided to accompany me midweek. I reminded him that we’ve been to Burning Man six times, and a wedding, presumably, happens once in a lifetime. He called me a hypocrite because I don’t believe in marriage, but will “sacrifice my commitment” to him to celebrate her commitment. He argues with such vehemence, I’m beginning to doubt my own judgment and wonder if he’s right. He’s acted like this before, but it’s become less frequent during our five years together. I don’t want to believe my boyfriend’s a selfish, manipulative ass, so…does he have a point? If not, how do I explain that you don’t abandon your friend on her wedding day to run around naked in the desert?

— Upset Bridesmaid

A: If your boyfriend’s ego were a pimple, it would burst and flood Vermont.

He’s actually demanding that the bride rebook the church, the caterer, the florist, and the hall, and tell hundreds of her guests to change their plans. Because he needs you there when he accepts his Nobel? No, because he wants to bum a ride with you to go to stand around the desert and watch middle-aged men and women flitting about in fairy wings and clown noses, painting daisies around each other’s nipples. It gets better. He’s telling you he’ll “never forgive” you. Because you slept with his brother, his best friend, or his brother and his best friend? Nope. Because he might have to pitch in for gas for a ride in some friend-of-afriend’s van that’s been modified into a giant rubber ducky in a tutu.

What your boyfriend’s doing to you is “gaslighting,” which, unfortunately, only sounds like lighting farts on fire. It’s actually insidious emotional abuse that gets its name from the 1944 Ingrid Bergman movie, “Gaslight,” about an heiress whose husband makes small changes around their home (like making their gas-powered lights flicker), then denies anything’s different, making her believe her sanity’s gone off its hinges. In a relationship, writes Dr. Robin Stern in “The Gaslight Effect,” you’re being gaslighted when somebody relentlessly pressures you to believe the unbelievable and do what you know you shouldn’t. Stern explains that the gaslighter “needs to be right in order to preserve his own sense of self and his sense of having power in the world,” while the gaslightee allows him to bully away her sense of reality and self because she fears losing his love and approval. Of course, in your case, it could have something to do with not wanting to think you’ve wasted five years with “a selfish, manipulative ass.” (Fart-play suddenly sounding inviting?) Just as you don’t have to believe in Santa to take your kid nephew to give his list of demands to some fat stranger in a fake beard, you don’t have to believe in marriage to appreciate what a huge life event it is for your friend.

Huge enough that it’s reasonable to “sacrifice” your “commitment” to attend a giant aciddropping fest in the desert. There are commitments, and then there are commitments, which is why there are bazillions of wedding photographers but few earning thousands of dollars shooting keepsake albums of people who carpool together.

Of course, you know all this. Or knew — until Clarence Darrow, as played by a big, soggy-diapered baby, started in on you. Clearly, this is less about a wedding than winning. But, in a healthy relationship, winning sometimes means letting the person you care about get their way. A loving boyfriend might be underthrilled that you’re attending the wedding, but he won’t hammer you about it until you’re not sure who you are or what you think. You either need to refuse to engage when he goes bully on you or refuse to stick around for more. If you do decide to leave, you shouldn’t have to worry about finding a new boyfriend, just about hiring bouncers for the line of guys wanting to date you after hearing the reason behind your breakup: “Yeah, seems my ex just couldn’t handle it when I said, ‘Bummer that I have to get all dressed up and go to this wedding, but you live it up best you can at that paganistic, psychedelic orgy in the desert.’”